1. Field of Invention
The present invention is related to utilization and access to wireless data services, and more particularly, to systems and method for automatic selection of the optimal data bearer that is actually available to a mobile station for a particular data transaction.
2. Description of Related Art
Although wireless data services such as the Wireless Application Protocol (WAP) are typically designed to work optimally with all air interfaces, optimizing the selection of an appropriate data bearer improves the quality of service (QoS) experienced by the end user of a mobile station and the improves overall performance of the wireless network. Optimal bearer selection strategies are typically tailored at least in part to improve transmission bit rates, decrease the bit error rate (BER), and to minimize call set-up and transfer delays.
One bearer selection strategy assigns a default data bearer to a mobile station. Whenever a data call is attempted by the mobile station, this default data bearer is used to establish the connection for the data call. The default bearer assigned to the mobile station may automatically change, for example according to the physical location of the mobile station as indicated by the MCC (Mobile Country Code) or other geographic indicator.
Another bearer selection strategy applies a bearer identification tag to data that is to be transmitted, the bearer identification tag identifying the data as best being transmitted over a specific data bearer. As an example, according to this strategy, when a WAP client initiates a data call using a first data bearer (which may be a default) the requested data is parsed and delivered over an optimal data bearer, which is identified according to the bearer identification tag assigned to the requested data.
Yet another bearer selection strategy initiates a data call using a first data bearer, and switches to a second data bearer at some point either before or during the data transaction according to a predefined bearer need condition, such as the completion of a set-up phase of the second data bearer, the amount of data to be transmitted, or the type of WAP application that is associated with the data.
More recently, technology has evolved such that a mobile station may be “aware” of whether it is attached to a network that supports a given optimal data bearer, such as GPRS, through a process of periodic registration. Thus, the mobile station is at all times ready to establish a data call using the optimal data bearer identified through registration.
Regardless of the bearer selection strategy employed, at times, the selected data bearer is unavailable, such as when network infrastructure issues render the bearer physically unavailable or where a roaming mobile station is prohibited access to a bearer by policy or capacity restraints of the Roamed Carrier. If a data call is initiated under these circumstances, the call will fail, even when other alternative—albeit less optimal—bearers are available. Typical attempts to solve this problem require the user of the mobile station to manually select an alternate data bearer, sometimes repeatedly. Users often are not aware manual bearer selection is available to them, or the users forget how to manually change to an alternate bearer to retry the data call. Furthermore, the average mobile station user may have no knowledge of the appropriate bearer to select as the next best alternative to the optimal or default bearer. Thus, such purported solutions are lacking particularly because a mobile station user is required to take action to establish a data connection that should be transparent.